Synthesis and evaluation of azaproline peptides as potential inhibitors of dipeptidyl peptidase IV and prolyl oligopeptidase

Summary A series of azaproline dipeptides with various N-substituents were synthesized as possible active-site-directed inhibitors of two proline-specific serine proteases, dipeptidyl peptidase IV and prolyl oligopeptidase. Compounds with semicarbazide, carbazate, acylhydrazine and sulphonylhydrazine structures were tested. Some compounds show moderate activity, i.e., in the millimolar range.     

A NEW SPECIES OF BEAKED WHALE MESOPLODON PERUVIANUS SP. N. (CETACEA: ZIPHIIDAE) FROM PERU

Mesoplodon peruvianus , a new species of beaked whale, is described on the basis of ten specimens which have either stranded or been captured between 11°12'S and 15°19'S latitude along the coasts of the provinces of Lima and Ica, south central Peru. This is the thirteenth living species of Mesoplodon recognized in the world's oceans. The animals that were examined were uniformly gray above, shading to lighter gray below. This whale is the smallest species of Mesoplodon (maximum body length 3.72 m) and is characterized by its teeth, which are small (31 to 65 mm long), ovate in cross section, and positioned 2.5% to 8.4% of the mandibular length from the anterior extremity, and posterior to the mandibular symphysis.     

A genome‐wide screen identifies genes that suppress the accumulation of spontaneous mutations in young and aged yeast cells

To ensure proper transmission of genetic information, cells need to preserve and faithfully replicate their genome, and failure to do so leads to genome instability, a hallmark of both cancer and aging. Defects in genes involved in guarding genome stability cause several human progeroid syndromes, and an age‐dependent accumulation of mutations has been observed in different organisms, from yeast to mammals. However, it is unclear whether the spontaneous mutation rate changes during aging and whether specific pathways are important for genome maintenance in old cells. We developed a high‐throughput replica‐pinning approach to screen for genes important to suppress the accumulation of spontaneous mutations during yeast replicative aging. We found 13 known mutation suppression genes, and 31 genes that had no previous link to spontaneous mutagenesis, and all acted independently of age. Importantly, we identified PEX19, encoding an evolutionarily conserved peroxisome biogenesis factor, as an age‐specific mutation suppression gene. While wild‐type and pex19Δ young cells have similar spontaneous mutation rates, aged cells lacking PEX19 display an elevated mutation rate. This finding suggests that functional peroxisomes may be important to preserve genome integrity specifically in old cells.     

Early Warning Signals for Rate-induced Critical Transitions in Salt Marsh Ecosystems

Ecosystems - Intertidal ecosystems are important because of their function as coastal protection and ecological value. Sea level rise may lead to submergence of salt marshes worldwide. Salt marshes...     

MAPK p38 and JNK have opposing activities on TRAIL-induced apoptosis activation in NSCLC H460 cells that involves RIP1 and caspase-8 and is mediated by Mcl-1

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce both caspase-dependent apoptosis and kinase activation in tumor cells. Here, we examined the consequences and mechanisms of TRAIL-induced MAPKs p38 and JNK in non-small cell lung cancer (NSCLC) cells. In apoptosis sensitive H460 cells, these kinases were phosphorylated, but not in resistant A549 cells. Time course experiments in H460 cells showed that induction of p38 phosphorylation preceded that of JNK. To explore the function of these kinases in apoptosis activation by TRAIL, chemical inhibitors or siRNAs were employed to impair JNK or p38 functioning. JNK activation counteracted TRAIL-induced apoptosis whereas activation of p38 stimulated apoptosis. Notably, the serine/threonine kinase RIP1 was cleaved following TRAIL treatment, concomitant with detectable JNK phosphorylation. Further examination of the role of RIP1 by short hairpin (sh)RNA-dependent knockdown or inhibition by necrostatin-1 showed that p38 can be phosphorylated in both RIP1-dependent and -independent manner, whereas JNK phosphorylation occurred independent of RIP1. On the other hand JNK appeared to suppress RIP1 cleavage via an unknown mechanism. In addition, only the activation of JNK by TRAIL was caspase-8-dependent. Finally, we identified Mcl-1, a known substrate for p38 and JNK, as a downstream modulator of JNK or p38 activity. Collectively, our data suggest in a subset of NSCLC cells a model in which TRAIL-induced activation of p38 and JNK have counteracting effects on Mcl-1 expression leading to pro- or anti-apoptotic effects, respectively. Strategies aiming to stimulate p38 and inhibit JNK may have benefit for TRAIL-based therapies in NSCLC.     

Test-Retest Reliability of Innovated Strength Tests for Hip Muscles

The burden of hip muscles weakness and its relation to other impairments has been well documented. It is therefore a pre-requisite to have a reliable method for clinical assessment of hip muscles function allowing the design and implementation of a proper strengthening program. Motor-driven dynamometry has been widely accepted as the gold-standard for lower limb muscle strength assessment but is mainly related to the knee joint. Studies focusing on the hip joint are less exhaustive and somewhat discrepant with regard to optimal participants position, consequently influencing outcome measures. Thus, we aimed to develop a standardized test setup for the assessment of hip muscles strength, i.e. flexors/extensors and abductors/adductors, with improved participant stability and to define its psychometric characteristics. Eighteen participants performed unilateral isokinetic and isometric contractions of the hip muscles in the sagittal and coronal plane at two separate occasions. Peak torque and normalized peak torque were measured for each contraction. Relative and absolute measures of reliability were calculated using the intraclass correlation coefficient and standard error of measurement, respectively. Results from this study revealed higher levels of between-day reliability of isokinetic/isometric hip abduction/flexion peak torque compared to existing literature. The least reliable measures were found for hip extension and adduction, which could be explained by a less efficient stabilization technique. Our study additionally provided a first set of reference normalized data which can be used in future research.     

Recombination in Polymer:Fullerene Solar Cells with Open‐Circuit Voltages Approaching and Exceeding 1.0 V

Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC₆₁BM. These devices achieve open‐circuit voltages (V_oc) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V_oc’s above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage‐dependent, steady state and time‐resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of –0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V_oc values above 1.0 V and that non‐fullerene acceptor materials with large optical gaps (>1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V_oc exceeding 1.0 V.